Towa became a sweeper admiring the legendary sweeper called, Orange-Eyed Messiah. The task of sweeper, which requires to sweep the monsters Adys is quite hazardous. On his first real attempt at fighting Adys, Towa encountered Kei, a former sweeper who saved him from being killed.Towa asked Kei to take him as a student. However, not only Kei plainly rejects Towas request, he tells Towa that he saw the Orange-eyed Messiah die!? An appearance by a mysterious man who seems to be connected to Kei showed up with a grudge from the past. Who is he and what is his relationship with the Orange-Eyed Messiah? Will Towa finds out about Keis past too?